- The following tumor characteristics: Low risk of recurrence after curative treatment defined as any of the following: for local ablation patients: single lesions ≤ 2 cm for surgical resection patients: single lesions ≤ 2 cm without microscopic vascular invasion, without tumor satellites and histologically well differentiated. ≥ 3 lesions or 2-3 lesions of which any are ≥ 3 cm in size (largest diameter, unidimensional measurement) prior curative treatment (surgical resection or local ablation) single lesion ≥ 5 cm (largest diameter, unidimensional measurement) in size prior local ablation.